Structure of heat sink

ABSTRACT

An improved structure of a heat sink is disclosed. The heat sink is composed of a ring body, fins and a bottom plate. The fins are radially arranged on the ring body. The bottom plate is fixed in the ring body for being placed a heat source. The heat sink can effectively dissipate the heat from the heat source.

BACKGROUND OF THE INVENTION

1. Technical Field

The invention generally relates heat sinks, more particularly to annular heat sinks.

2. Related Arts

Technology of heat dissipation plays an important role in the field of electronic apparatuses. With continuous development of consumer electronic apparatuses, the requirement and challenge of heat dissipation also increase. For example, tungsten lamps and halogen lamps have been replaced by light emitting diodes (LEDs). The main features of the LEDs are less power consumption, long service time, compact size and light weight. The LEDs also can emit various light so they can be extensively applied in many fields for indication and illumination. Although the LEDs generate less heat than conventional lighting devices, the problem of heat dissipation accompanied with high power LEDs still should be dealt with carefully.

Taiwan Patent Application Publication No. 200716911 discloses a heat dissipating device for LED lamp. '911 connects a high power LED lamp to a heat spreader via a heat pipe so that the heat from the LED lamp can be conducted to the heat spreader. However, '911's structure is considerably complicated and bulky.

Taiwan Utility Model Patent No. M317539 discloses an LED lamp. '539 employs a heat conducting post and a plurality of fins annularly connected thereto to constitute a heat dissipating module. The fins are radially disposed on the heat conducting post and form a recess at a top end of the heat conducting post for accommodating an LED.

In '539, however, the fins and heat conducting post can not be tightly connected so that the heat from the LED can not be effectively conducted to the fins through the heat conducting post. Thus, the heat dissipating efficiency of '539 is not good enough, and the LED tends to be damaged because of overheating. Furthermore, '539 has too many components and lacks secure positioning and connecting arrangement. Therefore, '539 is hard to be assembled and is uneconomical for manufacture.

SUMMARY OF THE INVENTION

A primary object of the invention is to provide an improved heat sink having a ring body and a seat plate, which can be securely and tightly connected to each other.

Another object of the invention is to simplify a structure of heat sink and to shorten production time in manufacturing process.

Another object of the invention is to enhance heat dissipation performance.

To accomplish the objects abovementioned, the heat sink is composed of a ring body, fins and a bottom plate. The fins are radially arranged on the ring body. The bottom plate is fixed in the ring body for being placed a heat source.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a preferred embodiment according to the invention;

FIG. 2 is a perspective view of the assembly of FIG. 1;

FIG. 3 shows a detailed status before the taper slot is pressed FIG. 4 shows a detailed status after the taper slot is pressed;

FIGS. 5A and 5B shows a process of the bottom plate being pressed;

FIG. 6 is a perspective view of a finished product shown in FIG. 1;

FIGS. 7A and 7B show another type of the bottom plate and how it connects the ring body;

FIGS. 8A and 8B show another type of the bottom plate and how it connects the ring body;

FIGS. 9A and 9B show another type of the bottom plate and how it connects the ring body;

FIG. 10 shows another embodiment of the bottom plate;

FIG. 11 shows a connection between the bottom plate and ring body;

FIGS. 12 and 13 show another connection of the bottom plate and ring body;

FIG. 14 shows another embodiment of the ring body;

FIGS. 15 and 16 show another embodiment of the bottom plate having a working fluid;

FIG. 17 is an exploded view of another embodiment of the ring body; and

FIG. 18 is a perspective view of assembly of FIG. 17.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, the first preferred embodiment in accordance with the invention is shown. The cylindrical heat sink 1 is composed of a ring body 10, a bottom plate 20 disposed in the ring body 10 and a plurality of fins radially disposed on the ring body 10. The ring body 10 is, but not limited to, a hollow cylinder. There are a plurality of longitudinally thin grooves 14 and taper slots 12 on an outer surface of the ring body 10. Both the thin grooves 14 and taper slot 12 are alternatively arranged. The bottom plate 20, which is made of copper, aluminum or iron, can be a single component or be composed of two components with different materials. A diameter of the bottom plate 20 is approximately equal to an inner diameter of the ring body 10 so that the bottom plate 20 can be fixed within the ring body 10. In a preproduction process, the fins 30 are arranged outside the ring body 10 and directed at the thin grooves 14 separately, and then the fins 30 can be fixedly embedded in the thin grooves 14.

In the shown embodiment, ring body 10 and fins 30 are fixedly connected by an extrusion process. Referring to FIGS. 3 and 4, each of the fins 30 is inserted in a thin groove 14. By using a punch 40 to extrude the taper slot 12, the thin groove 14 can grip the fin 30. As shown in FIG. 2, fins 30 are fixedly arranged outside the ring body 10. The taper slots 12 are extruded by the punch 40 to deform. Thin grooves 14 are pressed to tightly grip fins 30 as shown in FIGS. 3 and 4. Thus, both fins 30 and ring body 10 are fixed to be integrated as shown in FIG. 6.

Referring to FIGS. 5A and 5B, bottom plate 20 is pressed by a molding machine 4 from an originally smaller diameter to an extendedly larger diameter, so that bottom plate 20 can be fixed at a predetermined position in the ring body 10 to form an integrated module. As shown in FIG. 6, a space 200 is arranged in ring body 10 and bottom plate 20 for accommodating additionally electronic components.

On the other side, ring body 10, bottom plate 20 and fins can be made of different materials such as iron, copper, aluminum or alloy of previous metals to satisfy requirement of various circumstances as shown in FIG. 10. By using metal or alloy with better extensibility, the extrusion process can be performed more smoothly.

The junction between bottom plate 20 and ring body 10 can be noncomplete to retain air gaps. As shown in FIG. 7A, an outer side of bottom plate 22 can be of a regularly or irregularly lumpy shape. After being extruded, the extrusive portions 220 can be tightly connected to an inner wall of the ring body having thin grooves 14 and taper slots 12 as shown in FIG. 7B. Another available shape of the bottom plate 20 is shown in FIGS. 8A and 8B. In this embodiment, bottom plate 24 is of a flower shape with multiple petal. By these arrangements, gaps 222 or 242 can be retained after bottom plate 22 or 24 is pressed. The bottom plate 22 or 24 can provide not only to be placed additionally electronic components but also to enhance air convection through the gaps 222 or 242.

On the other side, ring body 100 can be rectangular as shown in FIGS. 9A and 9B. The rectangular ring body 100, which still has taper slots 12 and thin grooves 14, can match a rectangular bottom plate 26 with a regularly or irregularly lumpy peripheral. As the round ring body 10 abovementioned, rectangular bottom plate 26 also can be pressed to tightly connect the inner wall of the rectangular ring body 100. Additionally, ring body 10 or 100 also can be configured in a shape of semicircle, triangle, oval, cone, or irregularity. They can match corresponding bottom plates to form various outlines.

Referring to FIG. 11, besides the abovementioned manner, the connection between bottom plate 20 and ring body 10 also can adopt other processing approaches. A diameter of the bottom plate 20 can be approximately equal to or slightly smaller than an inner diameter of the ring body 10. The junction between bottom plate 20 and ring body 10 can be soldered or welded together, or infused thermal grease.

Referring to FIGS. 12 and 13, which shows other preferred embodiments according to the invention, cylindrical heat sink 1 includes a ring body 10 and a bottom plate 20 whose diameter is slightly larger than the inner diameter of the ring body 10. First, bottom plate 20 is aslant placed on an end of the ring body 10. Molding machine 4 presses bottom plate 20 to fix at a predetermined position as shown in FIG. 12. Alternatively, the inner wall of the ring body 10 can be provided with a step 20 a on a top end thereof. Bottom plate 20 is pressed by the molding machine 4 to insert into ring body 10 along the step 20 a.

Ring body 10 a is not limited to a hollow cylinder, it also can be configured into a shape shown in FIG. 14. The ring body 10 a has a bell at an end thereof. Bottom plate 20 is pressed by the molding machine 4 to be gripped at a predetermined position in the bell. A heat source (not shown), such as an LED lamp, can be placed on the bottom plate 20.

Furthermore, as shown in FIGS. 15 and 16, the bottom plate also can be a heat spreader having a working fluid 280 therein. The bottom plate 28 is fixed at in the ring body 10 and the heat source is placed on one side of the bottom plate 28. The heat dissipating efficiency can be increased by delivering heat of working fluid 280.

FIG. 17 shows another embodiment of the invention. In this embodiment, both ring body 50 and fins 60 are integratedly formed into a single element, and bottom plate 20 is fixed in ring body 50 as shown in FIG. 18. Similarly, bottom plate 20 can be placed by a heat source and the heat from the heat source can be dissipated by bottom plate 20, ring body 50 and fins 60. 

1. A heat sink comprising: a ring body; a plurality of fins radially disposed on an outer surface of the ring body; and a bottom plate fixed in the ring body for being placed a heat source.
 2. The heat sink of claim 1, wherein the ring body is provided with a plurality of thin grooves and taper slot, both of which are alternatively arranged.
 3. The heat sink of claim 2, wherein the thin grooves separately grip the fins by using a punch to extrude the taper slot.
 4. The heat sink of claim 1, wherein the ring body is one of circle, semicircle, oval, rectangle or cone.
 5. The heat sink of claim 1, wherein the ring body is of an irregular shape.
 6. The heat sink of claim 1, wherein a diameter of the bottom plate is equal to or slightly smaller than an inner diameter of the ring body.
 7. The heat sink of claim 6, wherein the bottom plate is connected to the ring body by soldering, welding or infusing thermal grease.
 8. The heat sink of claim 6, wherein the bottom plate is connected to the ring body by pressing the bottom plate to deform.
 9. The heat sink of claim 1, wherein a diameter of the bottom plate is slightly larger than an inner diameter of the ring body.
 10. The heat sink of claim 9, wherein the bottom plate is connected to the ring body by using a molding machine to press the bottom plate.
 11. The heat sink of claim 1, wherein the bottom plate is made of copper, aluminum or iron.
 12. The heat sink of claim 1, wherein the bottom plate is composed of two elements with different materials.
 13. The heat sink of claim 1, wherein the ring body and bottom plate are made of different materials.
 14. The heat sink of claim 1, wherein a junction between the bottom plate and the ring body is provided with at least one gap for air flow.
 15. The heat sink of claim 1, wherein the bottom plate is a heat spreader having a working fluid.
 16. The heat sink of claim 1, wherein both the ring body and the fins are integratedly formed into a single module. 